Submission #205674

#	Time	Username	Problem	Language	Result	Execution time	Memory
205674		SoGood	Combo (IOI18_combo)	C++17	100 / 100	59 ms	588 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>

using namespace std;

string guess_sequence(int N) {
  vector<char> v = {'A', 'B', 'X', 'Y'};
  string ans="";
  if (press("AB")) {
    if (press("A")) ans += 'A';
    else ans += 'B';
  } else {
    if (press("X")) ans += 'X';
    else ans += 'Y';
  }
  if (N==1) return ans;
  vector<char> vec;
  for (char d : v) if (d != ans[0]) vec.push_back(d);
  for (int i = 1; i < N - 1; ++i) {
    string ask = ans + vec[0] + ans + vec[1] + vec[0] + ans + vec[1] + vec[1] + ans + vec[1] + vec[2];
    int res=press(ask);
    if (res==ans.size()) ans += vec[2];
    else if (res == ans.size() + 1) ans += vec[0];
    else ans += vec[1];
  }
  for (char d : vec) {
    if (d==vec.back()) break;
    ans+=d;
    if (press(ans)==N) return ans;
    ans.pop_back();
  }
  ans+=vec.back();
  return ans;
}
/**
abcccbd
abacad
*/

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:22:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |     if (res==ans.size()) ans += vec[2];
      |         ~~~^~~~~~~~~~~~
combo.cpp:23:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |     else if (res == ans.size() + 1) ans += vec[0];
      |              ~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 95 / 95